近日，加拿大多伦多大学Sargent, Edward H.团队报道了小的碱离子将CO电还原成碳氢化合物而非氧合物。2026年1月29日出版的《自然-化学》杂志发表了这项成果。

电化学一氧化碳还原有望实现低碳强度化学品与燃料的合成，但该反应通常生成多碳产物的混合物，其选择性调控机制尚不明确。

研究组通过探究碱金属阳离子的影响规律发现，与二氧化碳电还原不同，锂离子能促进乙烯生成。利用原位拉曼光谱与模拟计算研究电解质-催化剂界面，发现电极表面的水合锂离子具有最强的氢键作用，而与中间体氧位点的阳离子-偶极相互作用最弱。这些相互作用抑制了碳原子的加氢过程，促进了与之竞争的氢解脱氧反应，从而导向烃类产物的生成。

基于这一认识，研究组通过锑掺杂降低了铜催化剂的氧亲和性，抑制了表面O-键合CHCHO*中间体的形成（该中间体是生成含氧化合物的关键前驱体）。结合上述策略，在膜电极组件电解槽中实现了79%的乙烯法拉第效率（电流密度150 mA cm^-2）和39%的能源效率。

附：英文原文

Title: Small alkali cations direct CO electroreduction to hydrocarbons rather than oxygenates

Author: Ni, Weiyan, Liang, Yongxiang, Cao, Yufei, Chen, Zhu, Miao, Rui Kai, Peng, Bosi, Liu, Zeyan, Liu, Yanjiang, Ze, Huajie, Wang, Xiao, Kim, Dongha, Park, Sungjin, Yu, Jiaqi, Papangelakis, Panos, Boureau, Victor, Imran, Muhammad, Wang, Qiyou, Ou, Pengfei, Li, Xiao-Yan, Xie, Ke, Dorakhan, Roham, Shirzadi, Erfan, Schatz, George C., Sinton, David, Ge, Jun, Zeng, Jie, Sargent, Edward H.

Issue&Volume: 2026-01-29

Abstract: Electrochemical CO reduction has the potential to enable low-carbon-intensity chemicals and fuels, but the reaction yields a mixture of multi-carbon products, and the underlying selectivity-driving mechanisms are unclear. Here we explore trends in alkali cations and find, in contradistinction to carbon dioxide electroreduction, that lithium promotes ethylene production. We study the electrolyte–catalyst interface using operando Raman spectroscopy and simulations and find that hydrated Li+ on the electrode surface has the greatest hydrogen bonding and the least cation–dipole interaction with the oxygen site on intermediates. These interactions suppress hydrogenation on carbon and promote the competing hydrodeoxygenation reaction that leads to hydrocarbons. We leverage this understanding and reduce the oxygen affinity of copper via antimony doping, suppressing the formation of the O-tethered CHCHO* intermediate on the surface that would otherwise lead to oxygenates. Combining these strategies, we achieve an ethylene faradaic efficiency of 79% at 150mAcm2 and an energy efficiency of 39% in a membrane electrode assembly electrolyser.

DOI: 10.1038/s41557-025-02061-x

Source: https://www.nature.com/articles/s41557-025-02061-x